Numerous laboratory studies have shown that carcinogenic nitrosamines can be formed from the nitrosation of environmentally prevelant tertiary amines in aqueous acid. Recent analytical studies and results from our laboratory suggest that tertiary amines in the environment are giving rise to nitrosamines by other than the accepted route. The investigation and elaboration of these routes which may involve nitrosation in non-acidic media or at much lower nitrite levels is proposed here and is important in establishing possible carcinogenic hazards resulting from tertiary amine nitrosation both in the environment and in vivo. In previous work we have shown that nitrosamines are formed from certain tertiary amines by elimination and substitution routes. The generality of this process as well as the interaction of tertiary amines with alkyl nitrites will be studied. We propose to determine the route(s) by which nitrosamines are formed in certain industrial processes as well. We are seeking to determine if sulfinic acids and their derivatives will act as efficient inhibitors of nitrosamine formation by virtue of their reaction with nitrite and we will seek to determine whether such compounds react with nitrosamines in such a way as to scavenge them. AZ1 new nitroso compounds and sulfinic acid derivatives will be tested in the Ames mutogen assay.